Air operated tool and control therefor



NOY 24, 1959 R. E. POWERS r-rrAL 2,914,032

AAIR OPERATED Toor. AND CONTROL THEREFOR United States Patent() AIR OPERATED TOL AND CONTROL THEREFOR Richard E. Powers, Monterey Park, and Charles W.`Weis, Arcadia, Calif., assignors to Powers Wire Products Company, Inc., Monterey Park, Calif., a corporation of California t e Application July z3, 1956, seal No. l$9,577

24 claims. (ci. 12u- 13) This invention relates to a tool for driving fasteners, for example staples and the like, and is more particularly concerned with the driveor operating means and a control therefor for such a device, it being a general object of the invention to provide a fully automatic fluid operated tool wherein the spring is eliminated that is ordinarily employed in such tools to return or retract the piston that is used to drive the staples.

This application is copending with our application Serial No. 599,450, entitled Air Operated Tool and Valve Therefor, filed on even date herewith.

Tools that employ .a reciprocating action are commonly driven or operated by a fluid actuated cylinder and piston means. Compound or double acting cylinder and piston means have long been available, however, in the particular type of tool under consideration, features of construction have made it advisable to avoid thel use of double acting cylinder and piston means. That is, the piston of this type of tool operates a driver or blade that is rectangular in cross section which makes it dicult to provide an adequate iluid seal surrounding said blade. Therefore, it has been the practice heretofore to employ a single acting cylinder and piston means and to provide a return spring. p 1

The use of return springs is a source of trouble in the operation and maintenance of tools of the type under consideration, since the return springs weaken and often break. A weakened spring will not return the piston the entire length of the stroke resulting in mal-functioning of the tool, and a broken spring will damage the mechanism by galling therpiston and the cylinder Walls. It is obvious that a spring has many disadvantages in tools of the type under consideration.

An object of this invention is to provide a completely automatic pneumatic or fluid actuated tool of the type under consideration that completes a working cycle of operation when supplied with a unit volume of uid under pressure. t

It is an object of this invention to provide a control for a tool of the type under consideration wherein the moving part or parts are actuated by fluid under pressure. By connecting the control that we provide to -a supply of lluid under pressure, the tool is put through a complete cycle of operation, which in the case illustrated includes a return stroke and a work stroke.

Another object of this invention is to provide a control for a pneumatic or uid driven tool having a double acting cylinder' and piston operating means that is adequately vented so that the working stroke of the machine is effective and not retarded. In the tools ofz the type under consideration, the working stroke must be rapid and not impeded by the entrapment of iluid in the cylinder below the piston. We provide a control'that adequately exhaustslfluid from `both the upper and the lower end of the cylinder.

It is also an object of this invention to provide a valve for delivering 4and exhausting a unit volumeof uid to and from the control Vthat VWe provide for open,

ation of a double acting cylinder and piston means in a tool of the type under consideration.

It is still another object of this invention to provide a control, the operation of which is initiated manually by a single movement of a trigger or the like, and vwhich acts to direct uid to cause reciprocation of a piston in one direction and thenv in the other direction. In practice, the normal unactuated position of the piston is at the lower end of the cylinder in which case the piston is iirst raised and then lowered. Both raising and lowering of the piston is done rapidly and under uid pressure that is handled by the control.

It is an object of this invention to provide a completely pneumatic or fluid operated tool and control therefor of the type referred to, that is simple, practical, dependable, and effective, and which is adapted to handle and drive fasteners, such as nails, pins, tacks and staples or the like.

The various objects and features of our invention will be fully understood from the following description of a typical preferred form and application of our invention, throughout which description reference is made tothe accompanying drawings in which:

Fig. 1 is a side sectional view of a fastener driven tool that incorporates the features ofthe present invention. Fig. 2 is an enlarged detailed sectional view of a portion of the structure shown in Fig. 1. sectional view of a portion of the structure taken as indicated by line V3--3 on Fig. l. Fig. 4 is a sectional view taken as indicated by line 4-4 on Fig. 1. Figs. 5 and 6 are detailed sectional views illustrating the control and valve that we have provided and showing views illustrating the control and valve that we have provided and showing the operative positions thereof, and Figs. 7, 8, and 9 are diagrammatic views illustrating the operation of the tool by the control and the valve.

The fastener delivering tool of the present invention is adapted to be handled manually and involves, generally, a frame A having a body portion 10 and a handle or grip portion 11, a head B carried by the frame A and adapted to direct fasteners into a piece of work, a magazine C for handling a supply of fasteners such as staples and cooperating with the head Bso that the staples are received and handled by the head, operating means` D having a blade or driving elementlZ, aguide means E for handling the staples and for accommodating the driving element of the means D so that it is continuously guided by the head B, latching means F adapted to cooperate with and control operation of the means D, a con- -trol means G adapted to govern the supply of uid under pressure to actuate the means D, and a valve means H adapted to supply a unit volume of duid to the control G.

The frameA is a substantially rugged but light-weight part that carriesk the elements of the tool, and which is shaped to be conveniently handled by a person. The frame A involves, generally, the body portion 10 and the handle or grip portion 11 above referred to. The body portion 10 is a simple elongate part having an openingy spaced laterally of the axis of the body and parallel` therewith. The seat 15 extendsrearwardly fromthe,n .face 13 to a shoulder'116 where the passage 17, that is rectangular in cross sectionalconiiguration, opens to the* exterior of the body. The shoulder 16 is normal to the longitudinal axis ofthe body. p

The handle or grip portion 11 is provided to give thev Vperson handling theV tool a convenient ineens to hold- Fig. 3 is an enlarged or the like, and also to include a control means" at the.

grip i111. It is to be understood that any suitable fluid pressure supply means can be provided without; affecting the present invention. When compressed` air is employed, as in the case illustrated, the hose of the power connection 18 is attached to the grip 11- through a`quick disconnect 20 and the valve means H is under control of a linger operatedl trigger 2-1.

The head B is, in effect, an extension of the body of the frame A and is provided to receive and deliver fasteners such as staplesto thework being acted upon by. the tool. The head Bfiscarried by the body 10 in the recess 14 and is provided with a longitudinal' guideway 22- that extends through and-opens at the ends of the head B. The head B has a bottom face 23 engaged withy the seat 15, it has a rear endface 24 normal to the axis thereof and engaged with the shoulder` 176, andit has a front end face 25 engageable with the work.

In the particularV form of the invention shown, the guideway `22 is adapted to handle fasteners o r staples S that are U-shaped and formedV ofwire, orv the like, having a pair of` sharpened ends (Fig. 4). The staples referred to are substantially elongate with straightparallel Shanks joined by a curved back. how the guideway 22 can be proportioned so that it will readily pass the staples with clearance and will act upon the staplesv to guide them as they are delivered through the head B and from the tool. The guideway 22 is a continuation of the passage 17 above described and guides` the driving blade of the. tool as well as the staples S that are handled thereby.

. A fastener or staple receiving opening 32 extends laterally through the head B, which opening enters the bottom face 23 of the head and` opens into the passage 22 so that the staples S fed to the. head B are properly guided and aligned with thepassage 22 before they are engaged by the driving blade 12 of the mechanism. The passage 22 has a staple guiding portion at the front of thefhead B of sufficient width to freely pass a fastenerkv or staple handled by thehead B, and the passage 22 has a blade guiding portion rearward of the rst mentioned portion that is of increased widthin order to accommodatethe relatively large .plunger or. driving blade -12 hereinafter described.

The magazine C is adapted to handle a supply orY stack of fasteners or U-shapedstaples S and involves, generally, acase 35 carried by the frame. A, a guide 36 within the case 35, a follower 37 adapted to advance the fasteners or staples, and a feed spring 38 yieldingly urging the follower toward the head B. The case 35 is carried by thevfront face13 ofthe body 10and is an elongate. part that* projects laterally from the frame A. The case 35 isA shelf-like in form andthe guide 36 is a core-like part that iscoextensive with the case 35 andV is carried between the side walls thereof. As shownin Fig. 4 ofthe drawings, the case 35 and guide36 are shaped so that a longitudinal passage 40 is formed, which passage conforms in general configuration tothe U-shaped staples which are handled by the head B.

The guide 36' enters the fastener or staple. receiving opening 32 and terminates in a at end 39 that occurs in the` plane of the bottom Wall ofthe guideway 22. The follower-37 conforms with the configuration of and is slideably carriedin the passage40 and is yieldingly urged toward thehead B by the follower 37 from entering the guideway 22. The fasteners or staples S are. inserted in the magazine C through thezopen tpthereofbysimply engaging them over thev guide 36 ahead of the follower 31. @a ghiasthe springas. Asv dearly strewn innig.

It will be apparent l, a spring biased latch 30 secures the follower 37 in a retracted position when desired, thus facilitating insertion of the fasteners.

The operating means D is provided to drive the fasteners or staples handled by the structure and in addition to the blade or driving element 12 includes a cylinder and piston mechanism 41. The cylinder and piston mechanism 41 is carried by the body 10 of the frame A on the longitudinal axis thereof, and is under control of the valve means G hereinafter described. The mechanism 4l involves a cylinder 42 and a piston 43 slideably operable in the cylinder. The piston 43 is actuated to retract and advance in the cylinder 42 in a manner common to tools of the type under consideration. However, the usual compression return spring is eliminated, which ordinarily is provided within the cylinder 42 ahead of the piston 43 to return the piston 43 to, av retractedI position.

The blade or driver element, 12 of the operating means D is essentially an elongate part rectangular in crosssectionalV configuration and terminates at its forward end in a at fastener or staple driving face 45. The blade 12 has a driving head at the forward end thereof which occupies the staple guiding portion of the guideway 22 when the driver is in the extreme advanced position and also has a stem that is guided by the blade guiding portion of the guideway 22- When the blade 12 is in the forward staple driving position as indicated in Fig. l of the drawings, the blade substantially occupies the passage 22. As shown, the blade 12 is provided with an inclined cam or face 48 that is pitched upwardly and rearwardly and which is provided to shift the guide means E hereinafter described.

In addition to the foregoing, the operating means D involves a snubber 27 that is provided to damp the piston 43 at the end of the work stroke. The snubber 27 is shown as a body of resilient material, such as rubber or the like, that is carried within the cylinder 42 and supported by :the lowermost head thereof. In accordance with the invention, the snubber 27 is a circular ring shaped part or body that is held in working position by theV walls of the cylinder 42 and which surrounds the driving bladeV 12 with substantial clearance. In practice, the piston 43 has a depending part lthat couples with the blade 12', the said depending part being smaller thanY the interior of thev ring shaped snubber 12. Thus, the depending part of the piston 43 enters the snubberl ring after which- :the piston engages the top 28 of thev snubber to compress` it. The, top 28 o f the snubber 27 is reinforced by a ring ofV metal, or the like, that is engageable with the piston. It-willv be apparent how the snubber 27` slows and stops advance of the piston 43 at the-end of the work'stroke.

The-guide means E is in the form of-a closure or gate 50 thatis pivotally carriedby the head B so that it normally substantially occupies the top of the head B. As shown, the gate 50'is elongate and is shiftably engaged with ythehead B by means of a pivot pin 51. The gate 50 normally occursin a position where it forms a con tinuation of the guideway'22. As shown, the gate 50 is; provided with-a cam` face 49 that cooperates with thel face 48 above referred to provided on the driver 12. By providing the cooperating cam facesl 48 and 49, thegate 50 is shifted ort-moved to the position shown in order-to allow the driver11f-2 to` advance. A- spring 50' is provided to yieldingly hold the gate 50 in a down or normal position where itr forms acontinuation of the guideway 22 and thereby guides the staples handled by the gun andalso guides the driver 12 of the gun. A headco'nstruction for a fastener driver of the'type referredv to is particularly set forth and claimed in Patent No. 2,784,406 to Richard E. Powers, issued March l2, 1957.

The latching means F that we employ/is adapted to cooperate'N with and control operation of the operating means D above. described. The meansF is provided- .to couple with and to hold the piston43 at the end of the return stroke and to release .the piston 43 when sufcient uid pressure has been established in the cylinder 42 to elect the desired work stroke. The latching means F involves, generally, an anchor 55 carried by the cylinder 42, a latching head 56 carried by the piston 43, a latching means 57 adapted to releasably couple the head 56 to the anchor 55, and a pressure responsive release means 58 adapted to actuate the means 57 to release the head 56 from the anchor 55. t

The end of thecylinder 42 remote from the head B is closed by a cap 59, the anchor 55 being in the form of a screw threadedly engaged through an opening in the cap. The anchor 55 is'an elongate part that projects axially into the cylinder 42 from the end thereof and is provided with a bore 60 to receive the head 56. The head 56 projects from the top of the piston 43 and is adapted to enter the bore 60 where it is engaged by the latching means 57. The head 56 is a tapered part with a widened top and the latching means 57 involves a pair of latching pins 61 that are releasably engageable beneath the widened top of the head. As shown, the pins 61 are carried in outwardly divergent angularly related slots 62 that open upwardly and outwardly from .the end portion of the anchor 55.` The slots 62 open into the bore 60 so that the pins are engageable with the head 56 when it is in the bore 60. A pressure plate 63 is provided to normally yieldingly urge the pins 61 into engagement with the head 56 under the inuenc of a spring 64. 1

The pressure responsive release means 58` actuates the latching means 57 to move the pins 61 in the slots 62 to releasethe head 56 from the anchor 55. The means 58 is responsive to the pressure of fluid in the cylinder 42 acting upon the piston 43 and involves a piston 65 adapted to lift the pressure plate63 to allow outward shifting of the pins 61. In practice, the piston 65 surrounds the anchor 55, there being a shoulder 66 on the anchor limiting movement of the piston 65 toward the piston 43. A spring 67 normally yieldingly urges the piston 65 toward the piston 43 andagainst the shoulder 66. The piston 66 has a skirt 68 that carries a retainer 69 that has lifting engagement with the pressure plate 63 when fluid pressure in the cylinder 42 shifts the piston 65. Adjustment of the latching means F is obtained by rotation of the anchor 55 to vary the compressing of the spring 67, the anchor 55 being locked in the adjusted position by a suitable lock nut. It will be apparent how the latching means F couples to the piston 43 until suicient fluid pressure is built up` in the cylinder 42 to operate the release means 58.

In accordance with the present invention, we have provided the control means G that governs the supply of fluid under pressure from the valve means H. In Figs. and 6 of the drawings, and in Figs. 7, 8, and 9, we have illustrated the particular control andvalve that we provide and the manner in which the piston 43 is controlled. As shown in Figs. 1 and 7, the normal unactuated position of the piston 43 is at the lower or head end of the cylinder 42, and when the tool is in this condition, the control G is unactuated and the valve means H is released and positioned asshown in Fig. l.

As shown in Fig. 8 of the drawings, the piston 43 is moved from the lower end of the cylinder 42 toward the upper end thereof, and when the tool is in this condition, the valve means H has been manually engaged and actuated to the position shown in Fig. 5. j

As shown in Fig. 9 of the drawings, the piston 43 has been fully moved to the upper end of the cylinder 42 (see Fig. 2), and whenthe tool lisin this condition, the valve means H remains actuated and the control means G is actuated to the position shown in Fig. 6. l f

. When the piston 43 has been moved to the position shown in Fig. 9 and is Alatched to the anchor55 (see Fig. 2), and when the valve means H isoperated to the position shown in Fig. 6, pressure is built up inthe cylinder 42 between the pistonsV 43 and 65 until the head 56 is released whereupon the work stroke of the tool is initiated. In order to accomplish the foregoing operation of the tool We have provided the control means G that is essentially a pressure actuated sequence valve which involves, generally, a valve body X, a valve element Y shiftably `carried in the body X, and a means Z yieldingly urging the element Y toward a normal unactuated position.

The construction of the control means G may vary as circumstances require and is so as to alternately admit and exhaust uid from the upper and lower ends of the cylinder 42. The valve of the control means G is a sequence valve adapted to receive fluid from a fluid pressurev supply, to first admit said iluid to the upper end of the cylinder 42. That is, the control means G is operable between twopositions, one where the uid is admitted to the lower end of the cylinder 42 and is exhausted from the upper end of the cylinder, and a second position where the uid is admitted to the Iupper end of the cylinder 42 and is exhausted from the lower end of the cylinder.

The control means G is formed in or carried by the frame A of the tool, and in the case illustrated, the body X is aseparately formed element or elements ma- -chined and then set in place in the frame A. The body X is best illustrated in Figs. Sand 6 of the drawings and involves upper and lower valve sleeves 70 and 71 that are carried in a recess or bore,72 provided in the frame A. As shown, the bore 72 is spaced laterally and parallel of the cylinder 42 and is substantially coextensive therewith. The bore 72 is a straight cylindrical bore preferably open at the top and bottom thereof.

Fluid handling passages connect the bore 72 with the valve means H hereinafter described and connect the bore with the upper and lower end portions of the cylinder 42. The valve means H is connected to the bore 72 by a passage 73 that opens into the bore intermediate the ends thereof. The upper end of the cylinder 42 is connected to the bore 72 by a passage 75 that opens into the upper portion of the bore, the passage 75 entering the cylinder 42 just below the piston 65. The lower end of the cylinder 42 is connected to the bore 72 by a passage 76 that opens into the lower portion of the bore. In addition to the foregoing connections, an exhaust port 77 opens into the lower portion of the bore '72 below the passage 76, and an exhaust port 78 opens into the upper portion of the bore 72 above the passage 75. The ports 77 and 78 open to the outside atmosphere at the exterior of the frame A.

The sleeves 70 and 71 are cylindrically shaped elements that are press fitted into the upper and lower portions of the b-ore 72 respectively, and each has an elongate inner cylinder wa1l'79 and 80 respectively, that slideably receive portions of the valve element Y as hereinafter described. The'passage 73 is a fluid pressure supply passage as well as an exhaust passage (see Fig. 1). A uid handling port or ports are provided in the upper sleeve 70 and are in communication with the passage 75, `while a fluid handling port or ports 91 are provided in the lower sleeve 71 and are in communication with the `passage 76. The ports 90 and 91 open through -the cylinder walls 79 and 80 respectively, and are in communication with the said passages through annular channels turned in the exterior of the sleeves 70 and 71, as shown.

The rvalve element Y is freely 'shiftable longitudinally of the sleeves 70 and 71 of the body X and as illustrated in Figs. 5 and 6 of the drawings, involves a valve stem 95 that interconnects upper and lower valve heads 96 and 97. The stem 95 and heads 96 and 97 are carried centrally of the cylinder walls 79 and 80 and are confined in proper working position by a plug that-is threadedly carried at the upper end of the sleeve 70 and by a plug 101 that is threadedly carried at the lower end of the sleeve 71. An extension 98 depends from the head 97 and is engageable with the plug 101 limiting downward movement of and longitudinally positioning the valve element Y.

The valve heads 96 and 97 have sealing engagement with the cylinder walls 79 and 80 of the sleeves 70 and 71, the seals being effected by rings 103 and 104, as shown, and when the valve element Y is in the unactuated position (see Figs. and 9), the head 96 allows exhaust of iluid from passage 75 through ports 90 to exhaust port 78, and the head 97 closes the exhaust port 77. When the valve element Y is in this unactuated position, the passage 73 is in communication with the passage 76 through the lower ports 91, and is closed to -the upper ports 90 and passage 75 to the end that uid under pressure effects raising or return of the piston 43 to the upper end of the cylinder 42.

When the valve element Y is actuated, as later described, to the position shown iu Fig. 6, the passage 73 is in communication with the passage 75 through upper ports 90 and closed to the lower ports 91 and passage 76 to the end that fluid under pressure will effect -the work stroke of the tool through operation of the operating means D and the latching means F, as above described. When in the fully actuated position the head 96 closes the exhaust port 78 from communication with the ports 90, and the head 97 opens the lower ports 91 to atmosphere through the exhaust port 77 thereby `freeing the piston for `downward movement in the cylinder 42.

The means Z that normally yieldingly urges the valve element Y to the unactuated position is an adjustable pressure exerting means and involves a simple compression spring 82 and a manually adjustable stop 83. The stop 83 is preferably in the form of a screw threadedly carried by the plug 100 to enter the upper end of the sleeve 70. The spring 82 is seated on the inner end of the stop 83 and acts against the valve head 96 to urge the head and the element Y to the position shown in Fig. 5. A lock nut 84 secures the stop 83 in the selected adjustment. It will be apparent how the Yvalve element is biased to resist movement of the element to the position shown in Pig. 6.

In accordance with the invention the valve element Y is automatically actuated by a differential action wherein the control means G senses the operative position of the piston 43 in the cylinder 42. As clearly illustrated in the drawings, the valve head 96 and mating cylinder Wall 79 in the sleeve '70 is substantially larger in diameter than the valve head 97 and the mating cylinder wall 80 in the sleeve 71. The iluid under pressure delivered by the passage 73 acts against the inner sides of the heads 96 and 97 to urge them outwardly in opposite directions from each other, the sleeves being vented to the outside atmosphere by the ports 77 and 78. In practice, the spring 82 is adjusted to withstand the fluid pressure necessary to actuate the piston 43 from the lower end of the cylinder 42 to the upper end thereof. It will be apparent that when the piston 43 reaches the upper end of the cylinder it is stopped and that continued flow of lluid into the cylinder will result in increased iluid pressure in the cylinder 42 and resulting in shifting of the valve element Y by means of the differential action above referred to. When the valve element Y reaches the position shown in Fig. 6 the second sequence or work stroke of the tool is initiated and the valve element Y remains in this position until the uid pressure is released therefrom by the valve means H.

The valve means H is a lluid pressure supply and exhaust means that admits and exhausts operating uid to and from the control means G hereinabove described. The valve means H is preferably formed in and carried by the frame A of the :tool andas shown, is housed 'in thefgrip V11. ln the case illustrated, 'the valve means H involvesa valve chest '85 formed or machined yin 'the grip 11, yand a slide 86 that is shiftably carried in the chest to controlthe flow of fluid, as above described. As shown, the chest extends through the grip 11 to open at both the front and back thereof, there being a recess 87 -at the "back of the chest and a recess 88 at the front of the chest. The vrecesses 87 and 88 are in the form of counterbores, the recess 87 handling the inlet of fluid under pressure and the recess 88 handling the exhaust of uid and yforming an exhaust means. A iluid pressure supply passage connects the recess 87 to the connection 18 while the recess 88 simply opens to the outside atmosphere vat the exterior of the grip 11 to exhaust uid.

The yslide 86 of the valve means H is freely shiftable in the chest 85 and involves a plunger 106 that is operable in the recess 88 and a valve disc 107 that is operable in the recess 87. A spring 108 is seated in a cap 109 that confines the -spring to the recess 87, the spring engaging and lyieldingly .urging the disc 107 into contact with a seat in the recess. An extension 110 projects from the plunger 106 and is engaged by and is operated by the trigger 21. When the valve means H is actuated to the position shown in Figs. 5 and 6, the disc 107 is lifted from the seat allowing passage of iluid under pressure to the control means G while the plunger 106 enters the chest 85 to close the exhaust recess. When the valve means H is released it returns to the position shown in Fig. 1 where the disc 107 is seated to close the recess 87 while the plunger opens the recess 88 to exhaust lluid yfrom the control means G. Upon release of uid from the means G, the valve element Y returns to the unactuated position readying the tool for the next succeeding work cycle.

The ports 91 normally handle a sutcient quantity or volume of fluid to allow for effective and etlicicnt operation of the piston 43 during the work stroke of the tool. However, under some circumstances, it may be desired to increase the rapidity of the work stroke by further elimination of back lpressure beneath the piston 43. As illustrated in Fig. vl of the drawings, we provide a pressure relief valve R that is spring biased to withstand the fluid pressure required to raise or return the piston 43 to the latching means F, and which allows free exhausting of fluid from the head end of the tool. A port 111 is formed `at the end of the cylinder 42 and is normally closed by the valve R. A spring 112 yieldingly urges the valve toward a normal closed position.

From the foregoing, it will be seen that we have provided an extremely practical and useful control for tools of the type under consideration. The control that we provide together with the pressure supply and exhausting valve results in a tool having a predetermined Worl; cycle. That is, the working element of the tool is controlled so that it is actuated sequentially by automatic shifting of the valve element Y that is pressure responsive and thereby senses the operative position of the said working element. The tool and control of the present invention results in a single complete work cycle each time the trigger 21 of the tool is manually actuated.

Having described only a typical preferred form and application of our invention, we do not wish tobe limited or restricted to the specific details herein set forth, but wish to reserve to ourselves any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described our invention, we claim:

l. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate body with a fluid pressure supply port intermediate its ends, with exhaust ports and fluid handling ports, a valve slide carried in the body `and operable between two positions, spaced `heads on the slide androne larger than the other, and means yieldingly .urging vthe slide to one position slide being responsive to the pressure of fluid handled' acting between` the heads thereof `to actuate the slide to the other position where it directs theow of fluid in the other direction.

2. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and theV like, including, `an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, exhaust ports and fluid handling ports, and a valve slide carried in the cylinder walls in the body and normally positioned to direct the flow of fluid in one direction and shiftable in response to the pressure of fluid handled to be shifted toward the cylinder wall of larger diameter to be positioned to direct the flow of fluid in the other direction.

3. A control for admitting and exhausting fluid from. the oppositeends of double-acting cylinder and piston units and the like, including, an elongate Valve body withupper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, exhaust ports and fluid handling ports, a valve slide carried in the cylinder walls in the body, and means yieldingly urging the slide to one position where it directs the flow of fluid in one direction, the slide being shiftable toward the cylinder wall of larger diameter in response tothe pressure of fluid handled and said slide being shiftable to the other position where it directs the flow of fluid in the other direction.

4. `A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port'therebetween, exhaust ports and fluid handling ports and a valve slide including, upper and lower valve heads operable in the upper and lower cylinder Walls respectively, the said slideV being normally positioned where it directs the flow of fluid in one direction, the said slide being shiftable toward the head of larger diameter in response to the` pressure 4of fluid handled and to the other position where it directs the flow of fluid in the otherV direction.

5. A control for admitting and exhausting fluid from the opposite Vends of double-acting cylinder and 'piston units and the like, including an elongate valve body with upper and lower cylinder Walls of different diam.

eter and with a fluid pressure supply port therebetween, exhaust ports and fluid handling ports, a valve slide including, upper and lower heads operable in the upper and lower cylinder walls respectively, and means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned where it directs the flow of fluid in one direction, and the said slide being shiftable toward the head of larger diameter in response to the pressure of fluid handled to the other position where it directs the flow of fluid in the other direction.

6. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the .supply port and exhaust ports respectively, and a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, the said slide being normally positioned to direct the fluid from thesupply port to the fluid handling port in one cylinder wall and to direct the flow of fluid from the fluid handling port in the other cylinder wall to the exhaust port at the outer end thereof, and the said slide being operable to be `positioned to `direct the fluid from the supply port to the fluid handling port at the said other cylinder wall and to direct the flow of uid from the fluid handling port in the first mentioned cylinder Wall tofthefexhaust port at the outer end thereof.

7. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, anelongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively, a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, and means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned to direct the fluid from the supply port to the uid handling port in one cylinder wall and to direct the flow of fluid: from the fluid handling port in the other cylinder wall to the exhaust port at the outer end thereof, and the said slide being responsive to the pressure of fluid handled and thereby operable to be positioned to direct the fluid from the supply port to the fluid handling port at the said other cylinder wall and to direct the flow of fluid from the fluid handling port in the first mentioned cylinder wall to the exhaust port at the outer end thereof.

8. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively,l a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, and an adjustable pressure means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned to direct the fluid from the supply port to the fluid handling port in one cylinder wall and to direct the flow of fluid from the fluidhandling port in the other cylinder wall to the exhaust `port at the outer end thereof, and the said slide being responsive to the pressure of fluid handled and thereby operable to be positioned to direct the fluid from the supply port to the fluid handlingxport at the said outer cylinder wall and to direct the flow of fluid from the fluid handling port in the frst mentioned cylinder wall to the exhaust port at the outer end thereof.

9. A control for admitting and exhausting uid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate valve body with upper and lower cylinder walls, the upper cylinder wall being larger in diameter than the lower cylinder wall, a fluid pressure supply portentering the body intermediate the said walls, an exhaust port at the outer end of each cylinder wall, a fluid handling port in eachcylinder wall between the supply port and exhaust ports respectively, and a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, the said slide being normally positioned to direct the fluid from thesupply port to the fluid handling port in the lower cylinder wall and to direct the flow of fluid from the fluid handling port in the upper cylinder wall to the exhaust port at the outer end thereof, and the said slide being operable to be positioned to direct the fluid from the supply port to the fluid handling port in the upper cylinder wall and to direct the flow of fluid from the fluid handling port in the lower cylinder wall to the exhaust port at the outer end thereof.

10. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate valve body with upper and lower cylinder walls, the upper cylinder wall being larger.in diameter than the lower cylinder wall, `a. fluidA pressure supply port enteringI the body. n.

termediate the said walls, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively, a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, and means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned to direct the fluid from the supply port to the uid handling port in the lower cylinder wall and to direct the ow of Huid from the fluid handling port in the upper cylinder wall to the exhaust port at the outer end thereof, and the said slide being responsive to the pressure of iluid handled and thereby operable to be positioned to direct the iluid from the supply port to the liuid handling port in the upper cylinder wall and to direct the flow of iluid from the fluid handling port in the lower cylinder Wall to the exhaust port at the outer end thereof.

11. A control for admitting and exhausting fluid from the opposite ends of double-acting cylinder and piston units and the like, including, an elongate valve body with upper and lower cylinder walls, the upper cylinder wall being larger in diameter than the lower cylinder wall, a fluid pressure supply port entering the body intermediate the said walls, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively, a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, and an adjustable pressure means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned to direct the fluid from the supply port to the uid handling port in the lower cylinder wall and to direct the flow of fluid from the fluid handling port in the upper cylinder wall to the exhaust port at the outer end thereof, and the said slide being responsive to the pressure of uid handled and thereby operable to be positioned to direct the iluids from the supply port to the uid handling port in the upper cylinder wall and to direct the flow of fluid from the fluid handling port in the lower cylinder to the exhaust port at the outer end thereof.

12. In combination, a uid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting uid from the opposite ends of the cylinder and including, an elongate body with a fluid pressure supply port intermediate its ends, with exhaust ports and uid handling ports, a valve slide carried in the bodyv and normally positioned to direct the flow of fluid in one direction and shiftable in response to the pressure of Huid handled to be positioned to direct the ilow of fluid in the other direction, spaced heads on the slide and one larger in diameter than the other, and a valve means for admitting and exhausting uid to the fluid pressure supply port and between the heads on the slide.

13. In combination, a fluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting fluid from the opposite ends of the cylinder and including, an elongate body with a iluid pressure supply port intermediate its ends, with exhaust ports and fluid handling ports, and a valve slide carried in the body and having two operative positions, means yieldingly urging the slide to one position where it directs the ilow of` fluid in one direction, said slide being operable to a second position where it directs the flow of fluid in the other direction, spaced heads on the slide and one larger in diameter than the other, anda valve means for admitting and exhausting fluid to the tluid pressure supply port andi between the heads on the slide.

1.4'.V In combination, a uid,l operated unit having. a

cylinder with. a piston shiftable therein, a control means'. foralternately admitting and exhausting: fluidi from theA opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, exhaust ports and fluid handling ports, a valve slide carried in the cylinder walls in the body and normally positioned to direct the ilow of fluid in one direction and shiftable in response to the pressure of fluid handled to be shifted toward the cylinder wall of larger diameter to be positioned to direct the ilow of iluid in the other direction, and a valve means for admitting and exhausting uid to the uid pressure supply port.

15. In combination, a fluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting fluid from the opposite ends of the cylinder and including, a'n elongate valve body with upper and lower cylinder walls of different diameter and with a uid pressure supply port therebetween, exhaust ports and Huid handling ports, a valve slide carried in the cylinder walls in the body, means yieldingly urging the slide to one position where it directs the flow of fluid in one direction, the slide being shiftable toward the cylinder wall of larger diameter in response to the pressure of iluid handled to the other position where it directs the ow of iluid in the other direction, and a valve means for admitting and exhausting uid to the uid pressure supply port.

16. In combination, a uid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting fluid from the opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween,.an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively, a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, the said slide being normally positioned to direct the uid from the supply port to the fluid handling port in one cylinder wall and to direct the flow of uid from the fluid handling port in the other cylinder wall to the exhaust port at the other end thereof, and the said slide being operable to be positioned to direct the uid from the supply port to the iiuid handling port at the said other cylinder wall and to direct the ow of fluid from the uid handling port in the rst mentioned cylinder wall, to the exhaust port at the outer end thereof, and a valve means for admitting and exhausting fluid to the uid pressure supply port.

17. In combination, a fluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting iluid from the opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder walls of different diameter and with a fluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively', a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned to direct the fluid from the supply port to the fluid handling port in one cylinder wall and to direct the flow of fluid from the liuid handling port in the other cylinder wall to the exhaust port at the other end thereof, and the said slide being responsive to the pressure of fluid handled and thereby operable to be positioned to direct the iluid from the supply port to the iluid handling port at the said other cylinder wall and to direct the ilow of fluid from the uid handling port in the rst mentioned cylinder wall to the exhaust port at the outer end thereof, and a valve means for admitting, and. exhausting, fluid lto the uid pressure supply port.

13 18. In combination, a iiuid operatedunit having a `cylinder with a piston shiftable therein, a control Imeans for `alternately admittingand exhausting tluidfromthe opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder walls of different diameter .and with a ud `pressure supply port therebetween, an exhaust port. at the outer end of each cylinder wall, a lluidhandling port in each cylinder wall betweeny the supply port and exhaustports respectively, a'valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, an adjustablelpressure meansyieldingly urging the slide to aI normal unactuated position, the said slide being normally positioned to direct the iluid from `the supplyport to` thetlu'id handling port inone cylinder wall and to direct the ow of fluid from the iluid handling port in the other cylinder wall to the exhaust port at the other end thereof, and the said slide' being responsive to the pressure of iluid handled and thereby operable to be positioned to direct the lluid from the supply port to the fluid handling port at the said other cylinder wall and to direct the flow of fluid from the lluid handling port in the lrst mentioned cylinder wall to the exhaust portat the outer end thereof, and a valve means for admitting and exhausting iluid to the uid pressure supply port.

19. In combination, a fluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting fluid from the opposite ends of the cylinder and including, an elongate body with a iluidv pressure supply port intermediate its ends, with exhaust ports and fluid handling ports, and a valve slide carried in the body and normally positioned to direct the llow of iluid in one direction and shiftable in response to the pressure of iluid handled to be positioned to direct the llow of iluid in the other direction, spaced heads on the slide and one larger in diameter than the other, and means yieldingly urging the slide to the first mentioned position, a latching means for releasably coupling to the piston and including, a pressure responsive means operable to release the piston when a predetermined iluid pressure is built up in the cylinder, and a valve means for admitting and exhausting fluid to the lluid pressure supply port and between the heads of the slide.

20. In combination, a iluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting lluid from the opposite ends of the cylinder and including, an elongate body with a iluid pressure supply port intermediate its ends, with the exhaust ports and iluid handling ports, a valve slide carried in the body and having two operative positions, spaced heads on the slide and one larger in diameter than the other, and means yieldingly urging the slide to one position where it directs the ow of iluid in one direction, said slide being responsive to the pressure of uid handled to be shifted to the second position where it directs the ow of lluid in the other direction, a latching means for releasably coupling to the piston and including a pressure responsive means operable to release the piston when a predetermined duid pressure is built up in the cylinder, and a valve means for admitting and exhausting fluid to the iluid pressure supply port and between the heads of the slide.

2l. In combination, a iluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting iluid from the opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder walls of different diameter and with a tluid pressure supply port therebetween, exhaust ports and tluid handling ports, a valve slide carried in the cylinder walls in the body, and means yieldably urging the slide to one position where it directs the ilow of lluid in one direction, the slide being shiftable in toward the cylinder wall of larger diameter in response to the pressure of lluid handled to the other position where it directs the` ow o f iluid in the other direction, a latching meansfor releasably coupling to the piston, and including a pressure responsive means operableto release the piston when a predetermined lluid pressure is built up in the cylinder, and a valve means for admitting andrexhausting iluid to the fluid pressure supply port; i 1

22. InA combination, a lluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting uid from the opposite ends of the cylinder and including, an elongate valve body withupper and lower cylinder walls of different,v diameter and with a fluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a luid handling port in each cylinder Wall between the supply port and exhaust ports respectively,

and a valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, the said slide being normally positioned to direct the fluid from the supply port to the iluid handling port in one cylinder wall and to direct the flow of uid from the supply port to the lluid handling port in one cylinder wall and to direct the flow of tluid from the fluid handling port in the other cylinder wall to the exhaust port at the other end thereof, and the said slide being operable to be positioned to direct the fluid from the supply port to the fluid handling port at the said other cylinder wall and to direct the llow of fluid from the fluid handling port in the rst mentioned cylinder wall to the exhaust port at the outer end thereof, a latching means for releasably coupling to the piston and including a pressure responsive means operable to release the piston when a predetermined lluid pressure is built up in the cylinder, and a valve means for admitting and exhausting fluid to the iluid pressure supply port.

23. In combination, a iluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting uid from the opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder Walls of different diameter and with a fluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a fluid handling port in each cylinder wall between the supply port and exhaust ports respectively, av valve slide including upper and lower valve heads joined by a stem and operable in the upper and lower cylinder walls respectively, and means yieldingly urging the slide to a normal unactuated position, the said slide being normally positioned to direct the iluid from the supply port to the fluid handling port in one cylinder Wall and to direct the ow of lluid from the iluid handling port in the other cylinder Wall to the exhaust port at the other end thereof, and the said slide being responsive to the pressure of iluid handled and thereby operable to be positioned to direct the uid from the supply port to the iluid handling port at the said other cylinder wall and to direct the ow of fluid from the tluid handling port in the rst mentioned cylinder wall to the exhaust port at the outer end thereof, a latching means for releasably coupling to the piston and including a pressure responsive means operable to release the piston when a predetermined lluid pressure is built up in the cylinder, and a valve means for admitting and exhausting fluid to the fluid pressure supply port.

24. In combination, a iluid operated unit having a cylinder with a piston shiftable therein, a control means for alternately admitting and exhausting fluid from the opposite ends of the cylinder and including, an elongate valve body with upper and lower cylinder walls of different diameter and with a iluid pressure supply port therebetween, an exhaust port at the outer end of each cylinder wall, a iluid handling port in each cylinder wall between the supply port and exhaust ports respectively, a valve slide including upper and lower valve heads direct the fluid from the supply port to the lluid handling o port in one cylinder Wall and to direct the ow of iluid from the tluid handling port in the other cylinder wall to the exhaust port at the other end thereof, and the said slide being responsive to the pressure of fluid handled and thereby operable to be positioned to direct the fluid from the supply port to the uid handling port at the said other cylinder Wall and to direct the ow of uid from the fluid handling port in the trst mentioned cylinder wall to the exhaust port at the outer end thereof, a latching means for releasably coupling to the piston and including a pressure responsive means operable to 16 release the piston when a predetermined Huid pressure is built up'in the: cylinder, and a valve means for admitting and exliaustin" Vfluid to theruid pressure supply port.

Referenties Cited in the' 'leA of thisY patent UNITED STATES PATENTS 41,484,679 Slater e 1 Feb. 26, 1924 Stone..e;.;..: 3, 2,619,072 Clarke et al. ..-u r.. v v Nov. 25, 195.2 2,774,968 Osborne et al. v Dee.r 25, 1-956 Y FREIGN PATENTS Great Britain v Aug. 26, 1940 

